Ext.namespace('sys');
sys.createNavTree = function(){
	var _tree = new Ext.tree.TreePanel({
		loader : new Ext.tree.TreeLoader({
			dataUrl :  'json/navigation.json'
		}),
		width : 170,
		split : true,
		lines : true,
		border : true,
		autoScroll : true,
		rootVisible : true,
		collapseMode : 'mini',
		collapsible : true,
		loadMask : true
	});
	var _root = new Ext.tree.AsyncTreeNode({
		id : '0',
		text : '功能菜单',
		draggable : true
	});
	_tree.setRootNode(_root);
	//_tree.setTitle('导航');
	_root.expand();
	return _tree;
}